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BUTE Department of Construction Management and Technology

20.10.2015

Why? Faster ▪ To reduce the duration of the process

Cheaper ▪ To reduce costs (where labour is expensive)

Easier ▪ To reduce (heavy) manual work

▪ A machine makes the work of many workers: excavator (0,5 m3) = 75 persons, tower crane (5 t, 50 m) = 140 persons

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Choosing construction equipment considering: The aim of the machine – the work to carry out –

the planned technologies The material / elements to work with The capacity needed The quality to achieve The conditions at the site The schedule The budget

Earthwork/ demolition

Lifting

Transportation

Concrete equipment

Heavy equipment

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Dozers, bulldozers A dozer is a tractor unit that has a blade

attached to the machine’s front. Wheel / Crawler dozer; Used for:

Stripping top soil;

Clearing vegetation;

Shallow excavation;

Spreading and grading soil;

Ripping of rock.

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Dozers, bulldozers

Dozers, bulldozers ripper

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Dozers, bulldozers, ripper

Loaders A loader is one machine in common use to pick

up excavated material. It consists of a crawler or wheeled tractor with a

shovel or a bucket mounted in front.

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Loaders Bucket capacity from less than 1 m3 up to 15m3

Scrapers, graders Are self-loading, transporting machines used for

general leveling of plane surfaces; To excavate and haul away large volumes; Can cut the soil layers from 15-30 cm. A scraper is a combination machine, it loads,

hauls and discharges material. Graders are multipurpose machines used for

finishing, bank sloping ,ditching, spreading, leveling and light stripping operations.

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Scrapers, graders

Excavators To excavate earth and load it into trucks or

deposit it; Variations:

Crawler-mounted: slow, but can operate on soft soil;

Wheel-mounted (rubber tires): moves faster and can travel on public roads;

Operated by hydraulics;

Operated by ropes; Several types

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Excavators: Power shovel / face shovel Operates from a flat , prepared surface; Works above the tracks, against a face or a bank; It digs by pushing the soil away.

Excavators: Power shovel / face shovel

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Excavators: Pull shovel / backactor / backhoe (hoe) The main difference is in the

position of the bucket (the reverse to that of the power shovel);

It is designed to dig below the level of the machine;

It digs by pulling the load toward the power unit.

Excavators: Pull shovel / backactor / backhoe (hoe) Bucket capacity: 0,2 m3-1,7m3

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Excavators: Pull shovel / backactor / backhoe (hoe)

Excavators: backhoe loader The combination of a backhoe and a loader

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Excavators: backhoe loader

Excavators: Dragline – an attachment used on a crane boom

It consist of a dragline bucket and some cables; The machine is operated by pulling the bucket

toward the power unit. It does not dig to as accurate as a pull shovel,

but it has larger working range; It is suited to digging below water level and in

mud / quicksand; It is used in mines.

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Excavators: Dragline Working range: 75-130m

Excavators: Dragline Bucket capacity up to 24-116m3

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Excavators: Clamshell A hinged bucket used on a crane boom Used for vertical excavating – above and

below ground level; Hung from a lattice-boom of a crawler crane

or hydraulic clamshell buckets on hydraulic hoes;

Special clamshell buckets for slurry walls.

Excavators: Clamshell

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Excavators: compact excavators Work in narrow places – even in buildings

Excavators: compact excavators Work in narrow places – even in buildings

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Drills and pile drivers Pile drivers may consist of a drop, mechanical or

vibratory hammer;

Drop hammer;

Single-acting hammer, double-acting hammer;

Diesel-hammer;

Hydraulic impact hammers, hydraulic drivers;

Vibratory pile drivers.

Drills – for creating piles and anchors.

Drills and pile drivers

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Compacting machines: The backfilled soil, gravel is to be compacted to

prevent distortion, settlement or softening; Backfill and compact always in layers! Types:

Static weight roller; Vibrating roller; Vibrating plate; Impact plate; Freefall hammer; High speed compactor.

Demolition equipment: Loaders and excavators; Hydraulic operated equipment.

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The aim is to lift construction material / elements / structures;

Lift greater loads and / or to greater heights; Types:

Pulley and hoisting tackle;

Cranes: mobile crane / tower crane / portal crane;

Elevators;

Other machines, equipment.

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Pulley and hoisting tackle: Simplest lifting machines ; Operated by hand or an engine

(electric motor or diesel engine) Material of ropes:

Natural – hemp;

Plastic fibers;

Steel cable.

Pulley and hoisting tackle:

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Mobile cranes: Have 3 sections:

Base frame mounted on crawler tracks or wheels;

Superstructure / power unit;

Boom.

Mobile cranes: Base:

Crawler-mounted: have greater capacity, but slow (8-10 km/h) prohibited to use public roads;

Wheeled: move faster (on public roads too), but need outriggers for lifting and have smaller capacity;

Boom:

Lattice-boom: slow to mount / demount;

Telescopic-boom: rapid and easily operated by hydraulics.

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Mobile cranes: Load capacity depends on:

The stability of the footing;

The strength of the boom (vary with boom length and extensions);

The counterweight (the manufacturers specify standard and maximum counterweight).

The working range is limited by the boom length and the length of the hoist cable.

Mobile cranes: Load capacity

diagram

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Mobile cranes:

Mobile cranes:

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Mobile cranes: accident

Tower cranes: Provide high lifting height and good working

radius; Takes up a very limited area on the site; Has a vertical tower with a jib:

Top-slewing (fixed tower) – swing circle mounted at the top of the tower;

Bottom-slewing (slewing tower) –swing circle located under the tower.

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Tower cranes: The main differences between top-slewing and

bottom slewing cranes are in the setup and dismantling procedures and in lifting height.

Bottom-slewing: self-erecting or fast erecting shorter because its revolving base

Top-slewing: requires more time (one day or more) and the assistance of other equipment (a mobile crane) to set up.

Tower cranes:

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Tower cranes:

Tower cranes:

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Tower cranes:

Tower cranes: Generally the crane stands on a foundation (mat

foundation or piles) Other types:

Rail-mounted (can travel with a load);

Crawler-mounted (has smaller capacity);

Tied-in crane (is tied in to the building);

Climbing crane (inside a very tall building).

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Tower cranes:

Portal cranes: It is associated with stockyard e.g. for precast

concrete elements, where lifting facilities are required.

The portal legs are mounted on rail tracks; The bridge is lattice frame construction; The portal beam supports an electric hoist

travelling on wheels.

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Elevators (hoists), other machines: Elevators are usually used after the loadbearing

structures are ready, for lifting smaller loads and workers.

Other machines:

Truck cranes;

Fork-lift trucks;

Hydraulic excavators;

Etc.

Elevators (hoists), other machines:

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Elevators (hoists), other machines:

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Transportation range:

On site – short range;

Off site – long range;

Material to be transported:

Solid elements (e.g. beams, bricks, doors, etc.);

Loose material (e.g. gravel, soil, cement etc.);

Fluid material (e.g. water, concrete etc.);

Fluids – Pumps Water and mud pumps:

For dewatering and clearing;

In wells.

Cement pumps:

To transfer cement (or plaster etc. in a form of a powder) – using compressed air.

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Pumps Concrete pumps:

Only for fluid concrete;

Mechanical pump – capacity 40m3/h distance h: 300 m, v: 40 m;

Hydraulic pump – capacity 120 m3/h distance h: 600 m, v: 300 m;

Squeeze pump – capacity 30 m3/h, distance h: 130m, v: 40 m;

Screw pump – capacity 100 m3/h, distance h: 40 m, v: 60 m.

Pumps

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Pumps

Trucks: Trucks are hauling units that provide relatively

low hauling costs because of their high travel speeds;

Trucks are described in terms of: Total number of wheels and driven wheels;

Capacity (m3) or payload (t);

Net weight empty, maximal weight, axle loads;

Engine power (kW/HP), speed;

Measures, turn radius.

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Trucks:

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Mixing concrete: Ready-mixed concrete (off site); On-site mixing.

Placing concrete: Buckets; Hand / power buggies, wheelbarrows; Chutes and drop pipes; Belt conveyors; Concrete pumps.

Consolidating and finishing: Vibrators (internal, surface and form vibrators);

Placing concrete: Bucket Wheelbarrow Chute Pump

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Ready-mixed concrete Conctrete is mixed in a central batch plant and

transported to the site;

Ready-mixed concrete Transit-mix trucks / mix trucks

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On-site mixing Only in cases when ready-mixed concrete is not

available or the quality of the concrete is irelevant;

Using a smaller mixer or a mixing plant.